Air-heater.



W. N. BEST.

AIR HEATER.

APPLICATION FILED MAY 3,19,5-

1,23 1 1 1 7 Patented June 26, 1917.

2 SHEETS-SHEET I.

W. N. BEST.

AIR HEATER.

APPLICATION FILED MAY 3,1915.

1,231, 1179 Patented June 26, 1917.

2 SHEETS-SHEET 2.

V/v m WILLIAM N. BEST, on NEW FYORK, 1\T. it.

AIR-HEATER.

Application filed May 3, 1915. Serial No. 25 ,412.

To all whom it may concern:

Be-it known that I, WILLIAM N. Bns'r,

a citizen of -the United States, and resident of New York city, borough of Brooklyn, county of Kings, and State of New York,

have invented certain new and useful Im- 'provements in Air-Heaters, of which the following is a specification. 1

This invention relates to certain improvements in apparatus for heating air so that the latter may be used for various commercial' purposes requiring a comparatively high temperature and freedom from the products" of combustion. The air may be used for heating buildings, ovens, or for drying cores, molds, japanned work, and various other objects requiring comparatively high temperature.

In the common type of air heatersnow used, for this purpose, the air must be delivered at about 400 F. and the conduits, drums, or other passagesthrough which air is passed while .being heated, are subject to very rapid; deterioration. This deterioration is particularly rapid when for any reason the supply of air is intermittent or is accidentally orunintentionally interrupted for even a short period of time. Air is ordinarily forced through the passages by an air blower and in case the blower should break or the fan fail to operate for any other reason, the excessive heat of the furnace raises the temperature of the walls of the passages to a red heat. These walls are ordinarily of steel tubing or cast metal and therefore when the blower is again placed in operation, the metal forming the said walls is repeatedly oxidized and ruined.

In my improved construction, I form the walls of the passagesof refractory material or other substance not subject to oxidation or injury by wide fluctuations in the temperature. The device in its preferred construction is so designed as to give a substantial foundation or bearingfor the passages and the parts are so supported by arches and standards that expansion or contraction does not injure them.- I may provide a single passage or any desired number varying in size and number according to the capacity or amount .of heated air required. The current of air through the passages'is preferably retarded and the air deflected so as to insure a proper contact of the air with the heated walls. The waste gases from the combustion chamber are preventedfrom commingling with the air being heated and may pass outinto a canopy or directly to achimney or stack. Any'desired fuel such for instance as coal, coke, gas or oil may be employed and the combustion chamber is preferably" so designed that it may be very readily adapted for use with different kinds of fuel.

Reference is to'be had to the accompanying drawings in which similar reference characters indicate corresponding parts in the several views and in which Figure 1 is a partial front elevation and 1 a partial transverse section through a heater constructed 1n accordance wlth my invention;

Fig. 2 is a central, vertical, longitudinal section through the form shown in Fig. 1;

Fig.3 is a side elevation; Fig. 4 is a transverse section through a modified form, and v I Fig. 5 is a central, longitudinal section through the form shown in Fig. 4.

In the specific form illustrated in Figs. 1, 2 and 3, I provide a casing formed with side walls 10and front and rear walls 11 and 12, preferably of refractory material. These may be supported and held rigid in respect to each other by an outer framework formed of metal channels, bars, or other structural shapes. The top of thechamber may be in the form of an arch 13 As shown in Figs. 1, 2 and 3, I employ three of these conduits, two of them being on the same horizontal level while the third is arranged at a higher elevation and above the space between the two lower conduits. A fan 16 or any other suitable form of air forcing mechanism is connected to one end of one of the lower conduits, while the opposite end of this conduit is connected to other lower conduit by a return bend 17.

This second lower conduit is connected to the upper conduit by a diagonal return bend 18 and any suitable form of delivery or other place where the heated air is to be 7 used. Y

For supporting the two lower conduits, I provide brackets or standards 20 extending lengthwise of the chamber and support the conduits preferably along their entire length. Resting upon the two lower conduits are a series of transverse arches 21 and resting upon these arches are a series of blocks 22 upon which the upper conduit 15 is supported. All of these parts are preferably of refractory material, such for instance as fire brick. Within the conduits I provide a series of baffles 23 which may be of any suitable character and which serve to deflect and break up the air currents and cause the air to come into intimate contact with the walls of the conduits. They also serve to conduct heat inwardly from the walls and provide additional radiating surfaces. These bafiies may be of refractory material and may, if desired, be formed integral with the peripheral walls of the conduits. As shown, the bafiles are in the form of a series of vertically extending bars or posts which'also serve to efiicien'tly support the upper walls of the conduits.

Below and between the two lower conduits is formed a combustion chamber 25 from which the heat-I'nayv'lr'ise between the two conduits as Well as along their outer sides to a series of outlet passages 26 arranged centrally along' the arched roof 13.

From these outlet passages, the gases of combustion may go direct to a stack or may be collected in a canopy or hood 27.

For producing the desired high temperature in the combustion chamber, various fuels may be employed. I have shown the device designed to be heated by oil fuel and have shown a reticulated bottom wall or floor 29 throu h which air may enter to the combustion 0 amber, and have shown a burner 30 designed to deliver a spray or sheet of atomized liquid fuel to the combustion chamber.

The atomizing of the fuel may be secured by compressed air or steam and the burner may, and preferably is, of the same general character shown in my prior Patent No. 752,195, granted February 16, 1905. It is of course evident that the atomizing and deliv cry of the fuel may be secured byother means. By removing the burner and substituting a grate, solid fuel, such as coal or coke, might be readily employed as the heating medium.

I do not wish to be limited to the specific arrangement or details of constructionhllustrated in the form above described, as vari- .of the other features of construction may be exactly the same as in the 'form shown in Figs. 1, 2 and 3. The return bends, the blower and the delivery conduit may be connected so that the air willenter and pass throughthe several conduits in any desired order. ,In both forms, I have shown the conduits substantially flat along the lower sides and curved on the upper side soas to be substantially D-shapedin cross section,

- although I do not wish-to belimited to this Specific form of conduit.

Various other forms, as well as other arrangements, may be employed within the scope of my invention.

Having thus described my invention, what I claimas new and desire to secure by Letters Patent is: 1

1. An air heater including acasing having front and rear walls of refractory material, a plurality of air conduits of refractory material disposed substantially horizontally and extending through said casing from the front to the'rear wall and. engaging with and partly supported by said walls, each of said conduits havin a plurality of inwardly extending, heat-radiating flanges'integral therewith, separate return bends disposed outside of said casing and connecting said conduits in series, a liquid fuel vaporizer delivering through said front wall and lengthwise of said casing beneath said con-.

air through said conduits'and. return bends.

2. An air heater including a casing having side walls and front and rear walls of re fractory material, an arched top wall supported by said side walls and having a series of gas outlets arranged along the upper portion thereof and lengthwise of said casing, a plurality of conduits of refractory material arranged in staggered relationship lengthwise of said casing and engaging with said front and rear walls, return bends separate from said conduits outside of said casing and connecting said conduits together in series, a liquid fuel vaporizer for deliverin vaporizing liquid fuel lengthwise of sai casing beneath said conduits and from said front wall toward said rear wall, separate ported by said side walls and having a series of gas outlets arranged along the upper portion thereof and lengthwise'of said casing, a plurality of conduits of refractory material arranged in staggered relationship lengthwise of said casing and engaging with said front and rear walls, return bends outside of said casing and connecting said conduits together in series, a liquid fuel vaporizer for delivering'vaporizlngliquid fuel lengthwise of said casing beneath said conduits and frorn said front wall toward said rear wall, separate air inlets to said casin beneath said vaporizer, means for delivering air through said-conduits and return bends, means for supporting certain of said conn air heater including a casing havday of May, A. D. 1915.

duits from the bottom of said casingyand a series .of refractory blocks spaced apart lengthwise of the casing and supporting the uppermost conduit from the lower ones.-

4. An air heater, including a casing, a

r plurality of air conduits of refractory material 'disposed substantially horizontally and extending through said casing from one wall to the opposite wall and engaging with and partly-supported by said walls, separate re turn bends outside of said casing and connecting said conduits in'series, a liquid fuel vaporizer delivering through oneof said walls and in the general direction of the length of said conduits beneath the latter and means for delivering air through said conduits and return bends in series Signed at New York city, in the county of New York and State of New York this firs ILLIAM N. BEST. 

